In recent years, vehicle window glass lifting devices for automatically raising or lowering window glasses are mounted on vehicles so that windows can be easily opened or closed.
Vehicle window glass lifting devices are provided with a drive mechanism arranged at a vehicle door for moving a window glass vertically and a control unit for controlling the drive mechanism.
Since the window glasses are electrically raised or lowered, the vehicle window glass lifting devices are generally provided with a mechanism to prevent pinching by window glass.
It is known that one of such mechanism is configured to monitor variation in rotational speed of a motor which drives a window glass, to determine that a foreign object is pinched by the window glass when a load increases and the rotational speed of the motor is reduced during raising the window glass, and to conduct various safety operations such as automatic lowering of window glass by reversing its movement direction.
In such a mechanism, however, the safety operations are conducted after a foreign object (part of human body, etc.) is actually caught. Therefore, a load is inevitably applied to human body and this causes a safety problem. For example, in this mechanism, since a region of, e.g., 4 mm from the closing end for the window glass is often configured as an insensitive zone so that full closing of the window glass is not incorrectly detected as occurrence of pinching, the safety operation may not be conducted when, e.g., a finger of a young child is trapped, hence, improvement is desired.
The vehicle window glass lifting device disclosed in PTL 1 solved such problems.
In PTL 1, it is described that a camera is located on the vehicle interior side with respect to the window glass as well as on the lower-front side of the vehicle with respect to the window glass, a foreign object to be possibly pinched by the window glass is detected based on an image captured by the camera, and various safety operations such as automatic lowering of window glass is conducted.
In PTL 1, it is also described that a marking applied around a window frame or an edge of the outline of the window frame, etc., is used as a feature amount for foreign object determination, and various safety operations are conducted when a foreign object is present between the markers, etc., used as a feature amount and the camera.
The detection of the foreign object to be possibly pinched by the window glass based on the image captured by the camera as described in PTL 1 allows a safety operation to be conducted before the object is pinched, and safety is thereby further improved.